# Local workload and benchmarks > Reproduce bounded latency and peak RSS measurements without external services. --- LLMS index: [llms.txt](/llms.txt) --- Run these tools from the Git checkout on macOS or Linux. They are development tools and do not run when an application depends on this crate. Build the optimized binary separately from measurement: ```sh cargo build --release --locked --example load_audit --features mosaic python3 scripts/run_load_audit.py --samples 32 --concurrency 4 --output target/load-audit/results.json ``` Repeat with concurrency 1 or 8 and a different output filename. The wrapper rejects more than 128 samples or concurrency above 16 and kills a run after 120 seconds. All network traffic goes to an ephemeral loopback server in the workload process. No credentials or public datasets are required. The driver calls the library tile APIs directly; the HTTP server supplies TIFF bytes. This is not an end-to-end load test of the example server's tile routes. The 64×64 synthetic Deflate TIFF has a 32×32 overview, three bands, four base blocks and a nodata corner. The server adds 2 ms to each GET. Cold samples include reader/client creation and metadata; warm samples use an already rendered tile's reader and decoded blocks. Mosaic samples use three separately identified URLs with identical fixture pixels and the Mean reducer. Outputs are 64×64 PNGs. Samples run in bounded batches; throughput includes batch barriers and is not an open-loop arrival-rate test. Each latency table reports nearest-rank P50/P95/P99. With 32 samples, P99 is the maximum sample; do not interpret it as a stable production tail estimate. The JSON includes cache counters before/after, individual cold cache snapshots, GET counts, prepared response bytes, maximum active server handlers, and the global work-budget estimate (its peak is cumulative across scenarios). “Response bytes” means payloads prepared by the server, not bytes proven delivered to a cancelled client. Cancellation cases use a 100 ms server delay. One case aborts task futures; others use an explicit cancellation handle (20 ms) or a deadline (10 ms). The latter launch eight requests against an admission limit of two and record all rejection/termination outcomes. Single-source readers are opened first so these cases exercise in-flight tile reads. Cold mosaic cases additionally cover client/metadata setup. Counters are sampled at return and after a 250 ms settling period; admitted-request permits and work-budget bytes are recorded. Remote server handlers may finish after client cancellation. These counters do not measure every background TLS initialization job or prove OS thread preemption of a running decoder. A memory-admission case submits eight 1024×1024 renders to a 64 KiB work budget. It requires eight resource-limit errors, no pixel GETs, and zero retained work bytes afterward. This checks early rejection, not peak memory under a full budget. The wrapper records UTC time, OS/architecture, logical CPU count, Rust version, commit and dirty status, executable SHA256, fixture SHA256, build-profile label, and child user/system CPU time. Peak RSS is the workload process's `wait4` `ru_maxrss` (bytes on macOS; KiB converted on Linux); compiler memory is excluded. It is a whole-run peak, not a per-scenario value or a process-tree total. These are bounded synthetic measurements on one machine. They do not establish production capacity, an adversarial codec memory bound, or behavior under an unbounded request stream. Fixture regeneration uses Python's standard library; Deflate bytes also depend on the installed zlib implementation. ## Resampler microbenchmark {#resampler} ```sh cargo bench --locked --bench resampler_bench ``` The six cases compare contiguous and strided bilinear sampling, each with and without a mask, plus masked and unmasked Average downsampling. This measures kernel cost, not HTTP latency or cross-CRS pipeline throughput. Criterion is a development dependency and is not a dependency of library consumers. --- Backlinks: - [Releases and crates.io](/docs/reference/releases/)